PageInfo-SortList: add clean up function
PageInfo-SortList: minor fix

* define |SortState| as a static handler: use |const| and CamelCase
* use |let| definition
* update comments
* clean up new lines
PrefButton: convert preset from hash to array

* ensure to tag the unique id to each buttons
PrefButton: minor fix

* convert the parameter of |updateState| into a optional hash
* define |BrowserProgressListener| as a static handler: use const and CamelCase
* rename |kID.CONTAINER_ID| to |kID.CONTAINER|
* update comments
* clean up redundant spaces and new lines
FindAgainScroller: update detection of hidden element
FindAgainScroller: support changes of |Map|

* Fx19: Map::clear
  see https://bugzilla.mozilla.org/show_bug.cgi?id=805003
* Fx19: Map::size
  see https://bugzilla.mozilla.org/show_bug.cgi?id=807001
TabEx: fix wrong variable
UI: minor fix: fix wrong comment
rewrite code for restart and arrange restart menu